1. Field of the Invention
The present invention relates to a multi-capillary electrophoresis apparatus comprised of a plurality of capillary columns, and a sample plate employed for introducing samples into the plurality of capillary columns. The multi-capillary electrophoresis apparatus is comprised of a multi-capillary array migration part provided with a plurality of capillary columns for injecting a plurality of samples one by one into the capillary columns and electrophoresing the samples, and an optical measuring part for irradiating the capillary columns with light and measuring absorbance by or fluorescence from the samples in the irradiated parts.
2. Description of the Prior Art
In general, the multi-capillary electrophoresis apparatus is employed for separating proteins or determining the base sequence of DNA. The multi-capillary electrophoresis apparatus for determining the base sequence of DNA is used for electrophoresing a DNA fragment sample prepared by labeling a primer or a terminator with a fluorescent material using Sanger's reaction and detecting fluorescence from the DNA fragment sample during migration, thereby determining the base sequence.
A DNA sequencer with high sensitivity, a high speed and high throughput is necessary for determining the base sequences of DNA such as human genomes, which have long base sequences. Accordingly, a multi-capillary DNA sequencer that has a plurality of capillary columns charged with gels has been proposed in place of those employing flat plate type slab gels. In comparison with the slab gels, the capillary columns can readily handle, inject and electrophorese samples at a high speed and make highly sensitive detections. If a high voltage is applied in slab gels, bands are spread due to the influence of Joulean heat, or temperature gradients are caused. Conversely, capillary columns have no such problems, but make highly sensitive detections with minimal spreading of bands under high-speed electrophoresis with the application of a high voltage.
In such capillary electrophoresis, samples are introduced into the capillary columns by a method employing pressure or an electrophoretic method applying a voltage. The method of electrophoretically introducing samples is widely employed because of simplicity in apparatus structure, readiness in operation and excellent controllability of parameters.
In the case of electrophoretically introducing samples, it is necessary to dip first and second end portions of the capillary columns in prepared samples and a buffer solution respectively while dipping electrodes such as platinum wires in the samples in the vicinity of capillary column ends.
In the case of holding the electrodes in the vicinity of the end portions of the capillary columns in electrophoretic sample introduction, electrode structures are complicated in the use of a multi-capillary electrophoresis apparatus, which arranges a plurality of capillary columns together in the form of an array and simultaneously electrophoreses samples.
After the samples are injected into the capillary columns by a method of applying a voltage, the capillary column ends must be transferred to a reservoir which stores a buffer solution for migration, and hence it takes a long time after sample injection for migration to begin. Therefore, automatization can speed up this process.